For certain fragile articles, such as bottles and the like, it is desirable to use shipping cartons containing interior partitions to prevent significant movement and breakage of the articles during shipment.
Such shipping cartons can be manufactured in either one or two pieces. The two-piece carton includes the carton itself and one or more separate dividers. Typically, assembly of the two-piece carton requires two pieces of equipment. The first piece of equipment constructs the carton while the second piece of equipment constructs the dividers. The dividers must then be inserted into the carton in order to form the completed carton. The one-piece carton, on the other hand, can be constructed from a single carton blank using one piece of equipment and thus presents a great cost savings over the two-piece carton.
Another advantage of the one-piece carton relates to its inherent durability. The separate dividers of the two-piece carton are not glued or attached to the carton, whereas the one-piece carton has integral and glued partitions making it more durable with greater stacking strength than the two-piece carton.
In addition, manufacturers of articles, such as plastic soda bottles, often ship empty bottles in the constructed carton to a bottler. The bottlers then turn the cartons upside-down to remove the empty bottles for entry into the filling line. With the two-piece carton, the separate dividers tend to slide out or become misaligned during this process. However, in the one-piece carton, the dividers are integral to the carton so that they cannot slide out or become misaligned and thus need no further adjustment when the filled bottles are reloaded into the cartons.
U.S. Pat. Nos. 1,808,922 and 3,082,929 both disclose a single carton blank which can be folded into a rectangular carton with integral interior partitions. Such a single blank comprises a bottom wall, two side portions and two end walls. As suggested in U.S. Pat. No. 3,082,929, the blanks can be erected by folding and sealing the side portions into an open-ended rectangular tubes. The rectangular tubes and end walls are then folded and sealed together to form the completed carton.
The present invention thus relates to an apparatus and method for erecting from a single carton blank a one-piece carton with integral interior partitions by a series of cooperating folding and sealing operations. These operations are performed automatically, efficiently and economically by the apparatus of the present invention. The flat carton blanks can be conveniently and economically shipped to the user who can assemble the carton at the manufacturing location of the articles to be shipped.
The apparatus according to the present invention can be constructed to manufacture cartons of different sizes and each apparatus is adjustable to provide for slight variations in carton size. The apparatus is designed to produce about 25 cartons per minute.